Today’s Wonder of the Day was inspired by Meghann. Meghann Wonders, “What is Occam's Razor?” Thanks for WONDERing with us, Meghann!

Have you ever WONDERed how doctors diagnose their patients? What about how mechanics find out what’s wrong with a car? The truth is, these two occurrences often have something in common. They both employ Occam’s Razor. 

Have you ever heard someone say, “Keep it simple”? That’s the basic idea behind Occam’s Razor (or Ockham’s Razor). It’s the idea that the simplest explanation to any question is most likely the correct one. Occam’s Razor is named for a town in England—Ockham. That’s where a philosopher named William lived during the Middle Ages. However, the idea behind Occam’s Razor started long before William of Ockham.

Many think Occam’s Razor goes all the way back to Aristotle. Since then, it’s been used to support many ideas in philosophy and science. Even Galileo used Occam’s Razor to support his model of the solar system.

Can you apply Occam’s Razor to your own questions? Sure you can! Let’s think about an example. What’s your favorite type of cookie? Peanut butter? Chocolate chip? Imagine a family member made a batch of your favorite cookies, and you know there’s only one left. You’ve just gotten home from school, and you head straight for the kitchen. You’re going to get that last cookie.

When you reach the kitchen, your older sibling walks out, brushing crumbs off of the front of their shirt. You walk into the kitchen, head straight for the cookie jar, and… the last cookie is gone! What happened? After thinking, you have a few guesses. 

First, there’s the sibling you saw leaving the kitchen. Those crumbs they were brushing off—were they from the cookie you wanted? Second, one of your grandparents also likes cookies. Maybe they came over in the middle of the day and took the last cookie. Finally, an alien could have visited from outer space. They took the last cookie because it was their favorite, too.

If you’re thinking your older sibling took the last cookie, we agree! Think about it—that’s the simplest explanation. To believe your grandparent took the cookie, you’d have to assume that they knew the cookie was there. You’d also be assuming that they had time to go to your kitchen and take it. To believe that an alien took the cookie, you’d have to assume aliens exist. You’d also have to assume they used space travel, entered your house, and knew what a cookie was. That’s a lot of assumptions!

Simple explanations rely on fewer assumptions. You saw your sibling leaving the kitchen, and you saw crumbs on their shirt. You don’t need to do much assuming to believe they’re the culprit

Does Occam’s Razor always work? Not necessarily. There are plenty of phenomena in the world that turn out to be pretty complex. However, Occam’s Razor helps people decide where to start. In science, experts test the simplest explanations first. That’s because they’re easier to disprove, which helps scientists find the correct answer faster. Police officers also use this method when solving crimes. They can rule out simple explanations fast to narrow down what really happened.

How else can you apply Occam’s Razor? What mysteries of the world would you like to solve? From everyday questions to the bigger problems of life, many people find Occam’s Razor very helpful. Just remember to keep it simple!

Standards: CCRA.R.4, CCRA.L.3, CCRA.L.6, NGSS.ETS1.C, CCRA.R.1, CCRA.R.2, CCRA.SL.1, CCRA.SL.2, CCRA.W.2, CCRA.L.1, CCRA.L.2, CCRA.R.10

Wonder What's Next?

Learn the truth behind a legend with tomorrow's Wonder of the Day!